Date:         Sun, 17 Dec 2006 18:56:50 -0800
Reply-To:     Don Hanson <dhanson@GORGE.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Don Hanson <dhanson@GORGE.NET>
Subject:      Cooling and heating anomolies 84 w/I-4 transplant..
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Ok, I haven't been around the list here for long enough to know if I am gonna get a bunch of "Told-ja-so's" and "What did you expect?" and "serves you right for thinking you know more than Fritz and Franz at VW" but I am going to ask away.  If there is better place to get some ideas, point me there if you will, or if this is something that also happens to WBX vans, then perhaps someone would be so kind as to clue me in.  I am sort of new to  the W/C vans..

  So a while back I was having overheating issues and did a bunch of work on the cooling system..New water pump, thermostat, coolant temp sensor, Flushed the radiator and replaced a couple of hoses. New belt, plus added Dextron coolant as per specs.  Still  having overheating till a Vanagon savvy friend pointed me to the radiator bleed screw.  That pretty much solved all, for a while..But today, my front heater started blowing cold..."Uh oh" says I, "My coolant is low or my belt is loose"..The temp gauge climbs up to about 1/2 way to hot with the defroster blowing ice cold air and then..the heater gets hot again and the temp gauge goes right down to where it runs, which is just into the warmed up range... then again, cold air and gauge climbing..for about 4 miles, then again warm air and back down  with the temp...No symmetry to the episodes..other than for about a week everything was just fine until today.
    So, I get back to my shop and find the coolant slightly low...it took about 2 quarts..Then, I jack up the rear and open the bleed screw on the rad...put another couple of quarts into the rear coolant res. till it burps the radiator out and I get coolant overflow there at the bleed screw.  
     OK, some more data points..The motor is a 92 Cabriolet motor (1.8 liter 8 valve) and I've driven it cross country without any heating problems. No problems till just  recently.  The front heater/defroster has never blown hot at idle that I can recall, but once off idle, it works just fine.  The rear heater..I noticed a slight coolant odor when I first turned it on, so I checked that also and found it a little weepy at one hose..tightened that and opened the bleed screw, which is 'semi-stripped'..There was coolant right there, no air at the hole where the bleed screw came out..I will probably put some silicone in the threads to seal that for sure...The rear heater blows hot whenever it is on...when, of course, the coolant is up to temp..  Maybe I need to change the waterpump pully to get more coolant circulation?
  So, is there some kinda valve or temp. sensor that controls flow up to the front..the radiator and the heater?  I seem to have intermittent coolant circulation up there..Remember, new water pump, flushed radiator, and fresh anti-freeze.  Belt is new and properly tensioned...
  Should I be thinking the radiator needs to be replaced?  Anyone tried one from the Bus Depot..they have a killer price on rads...

  Thanks in advance..and I don't mind being "told ya so" about having a changed non-standard Vanagon..
  Don Hanson